Conventionally, there are known various vehicle collision sensors for detecting collision occurrence in the event of a vehicle collision. For example, Japanese Patent Unexamined Publication No. H05-45372 discloses an arrangement of canceling insulation between two conductors so as to make them conductive with each other when a vehicle side door is subjected to an impact exceeding a certain value in the event of a vehicle lateral collision, thereby detecting the occurrence of collision against the vehicle side door as an electric signal.
By the way, with regard to an arrangement of restraining a vehicle occupant by an occupant restraint system such as an airbag during a vehicle collision, the demand for technology of improving the occupant restraining capability has been increased. Accordingly, the demand for developing a sensor which is effective for improving the detection quality in order to detect rapidly and securely occurrence of a vehicle collision has also been increased.